Power shovel



Jan. 18, 1944. w. M. HUSTON POWER SHOVEL INVENTOR 2 Sheets-Sheet 1 Filed March 15, 1941 Mm /7/. m

YM. ATTORNEY Jan. 18, 1944. HUSTON 2,339,700

POWER SHOVEL Filed March 15, 1941 2 Sheets-Sheet 2 W myzsvuTo'R ATTORNEYJ Patented Jan. 18, 1944 UNITED STATES PATENT OFFICE POWER SHOVEL William M. Huston, Lima, Ohio Application March 15, 1941, Serial No. 383,485

6 Claims.

This invention relates to power shovels, and more particularly to that type of power shovel having a dipper with dipper stick mounted for hoisting and crowding movement.

In certain prior art shovels crowding effort was secured from a drum on the power shaft; in others from the dead end of the hoist cable. In the former case, it has been common to employ a crowd clutch associated with the power shaft and delivering power to a chain transmission extended to the shipper shaft, the hoist line in this arrangement being dead-ended at a fixed anchor on the boom or gantry. n the other hand, when employing the dead'end pull of the hoist cable, it has been common to reeve the dead end of the hoist cable on a drum associated with the shipper shaft, the crowd eflort being controllable by a second cable also reeved on the shipper shaft drum and on another drum provided with a controllable brake,

One of the principal objects of the invention is to provide a shovel capable of exerting digging action of greater force Without increasing strain and wear and tear on the machine.

The invention is particularly useful in making possible the exertion of substantially increased crowding effort, without an increased effort on the part of the prime mover and without appreciable increase of wear and tear on the machine. In fact, a decrease in the strain on the machine, including the power plant, can be secured along with an increase of crowding effort.

The foregoing is accomplished by deriving crowding efiort both from the power shaft and from the dead end of the hoist cable.

Alternatively, the present invention provides for operation with the hoist cable dead-ended at a relatively fixed point, the crowd effort being secured only through the crowd clutch and transmission from the power shaft to the shipper shaft.

More specifically, the foregoing advantages are attained by the employment of a crowd drum mounted on the power shaft coaxially with the hoist drum, the crowd drum being interconnected with the shipper shaft, a by a chain drive, and the hoist cable being reeved to the hoist drum over one side thereof and to the crowd drum over the opposite side thereof. The crowding effort derived from the dead end pull of the hoist cable is controllable by a brake associated with the crowd drum and, in addition, a crowd clutch associated with the crowd drum may serve to decorrespondingly liver additional crowd effort through the transmission extended to the shipper shaft.

When coupled up in this manner, although the rate of digging is relatively low, the digging effort, and especially the crowding effort, may be rendered considerably greater than in either of the prior common types of shovels. On the other hand, where more rapid digging action is desirable, as in cases where the increased crowding effort is not required, the shovel of this invention is readily adapted to conversion to the type in which the dead end of the hoist cable is anchored on a relatively fixed part and crowd effort is secured only through the crowd clutch associated with the power shaft.

Still further, when the hoist cable is reeved to the crowd drum, a very wide range o crowding effort is attainable, maximum effort being secured with the crowd brake released and the crowd clutch engaged, and a lesser effort secured with the clutch released and the brake more or, less tightened. Tightening of the crowd brake also increases the speed of hoisting, which is of advantage since rapid hoisting of the loaded dipper may be effected after the initial pd'rtion of the digging stroke. Thus the shovel of the present invention not ,only provides increased digging action but, in addition, retains the desirable capability of high speed hoisting.

How the foregoing objects and advantages are attained will appear more fully from, the following description referring to the accompanying drawings, which illustrate the preferred embodiment of the invention, and in which- Figure 1 is a side elevational view of a power shovel constructed in accordance with the present invention, many parts being omitted or shown in outline for the sake of clarity;

Figure 2 is a fragmentary top plan view of a portion of the mechanism appearing in Figure 1;

Figure 3 is a fragmentary plan view on an enlarged scale taken substantially as indicated by the line 3-3 of Figure 1, the view showing the power and jack shafts and their associated parts, as constructed in accordance with this invention, certain devices being illustrated in section; and

Figure 4 is a side elevational view, similar to Figure 1, of a portion of the mechanism shown in Figure l, but with the hoist cable dead-ended by a fixed anchor on the boom.

As seen in the drawings, the shovel comprises a cab base 5 which is mounted for swivel movement on a truck 6 having the customary crawler tread 1. The boom 8 is plvotally connected with the cab base as at 9-3, the boom being suspended from the gantry III by means of multiple cables ll passing over sheaves 12. The cables II are reeved to the power hoist drum on the jack shaft 13 in a manner which need not be considered in detail herein.

The dipper I4 is mounted on the dipper stick IS, an extended length of the stick being provided with rack teeth l6, and the stick being guided by the saddle block l1 having supporting sleeves I8-l8 for pivoting the same on shipper shaft [9. A pinion meshing with rack I6 is rotatable on shaft l9 and is driven by a sprocket 2| connected with the pinion by a hollow shaft passing through one of the sleeves or trunnions l8. A chain 22 is associated with sprocket 2| and passes around sprockets 23 and 24, the latter being mounted on a shaft 25 coaxial with pivots 93 for the boom. Shaft 25 carries a second sprocket 26 which receives power from a chain 21 referred to more fully hereinafter.

Hoisting of the dipper is effected by a hoist cable which cooperates with padlock sheave 23, the live and dead ends 29 and 30 of the cable passing over boom point sheaves 3| for connection with other devices described hereinafter.

Power for operation of the shovel is derived from engine 32 having a roller chain drive 33 to the jack shaft l3, this shaft being, in turn, geared to the power shaft 34 by the gearing 35-36.

The reversing shaft 31 for propel and swing is geared as indicated at 38 with the gear 36.

In accordance with the present invention, the live end 29 of the dipper hoist cable is associated with the hoist drum 3! journalled on power shaft 34 and connectible therewith by a clutch incorporated in the clutch-and-brake unit indicated at 40. The dead end 30 of the hoist cable is adapted alternatively to be associated with the cable anchor 4|, as shown in Figure 4, or with the crowd drum 42, as shown in Figures 1 and 2.

' Crowd drum 42 is joumalled, coaxially with the hoist drum 39, on power shaft 34 and has associated therewith a clutch and brake unit 43. This unit, as clearly appears in Figure 3, includes a drum flange 44 which is rigid with the crowd drum 42 and which cooperates with a controllable clutch 45 of known type having a driving element 46 keyed to the power shaft 34. A controllable brake band 41 surrounds the drum flange 44.

Crowd out and crowd retract sprockets 48 and 49 rigid with crowd drum 42 cooperate, respectively, with crowd chain 21 and crowd retract chain 50, the latter being associated with sprocket 5| joumalled on jack shaft l3 and adapted to be connected therewith by means of the crowd retract clutch 52.

With the jack shaft [3 there are also associated the customary boom hoist clutch 53 and boom lowering clutch 54, the operation of these parts not being described in detail herein since they form no part of the present invention per se.

In considering the operation of the mechanism described, reference is first made to the condition represented by Figure 4, in which the dead end 30 of the dipper hoist cable is anchored as at 4| to the boom 3. In this condition, the shovel may be operated in accordance with more or less general practice. The hoisting movement is effected by actuation of the hoist clutch in the unit in order to connect the hoist drum with the power shaft 34. The crowding movement is effected by actuation of the crowd clutch in order to connect the sprocket 43 with power shaft 34.

In accordance with the present invention, however, provision is made for alternatively connecting the dead end 30 of the dipper hoist cable with the crowd drum 42, this condition being indicated in Figure 1, from which it will be seen that the dead end 30 extends over the upper side of the crowd drum 42, the live end 23 of the hoist cable extending under the lower side of the hoist drum 33. In this way the dead end pull of the hoist cable may serve to rotate the sprocket 43 and thereby actuate chain 21 and the remaining parts of the crowd mechanism. This conversion of the dead end pull of the hoist cable into crowding effort may be regulated by the controllable brake 41. 7

Although the hoist cable speed may be increased when it is coupled with the crowd drum (the action of the cable being divided between hoisting and crowding), a relatively slow and steady digging action is obtainable, such as is suitable where rock is encountered, this being desirable both from the standpoint of production and from the standpoint of wear and tear on the machine. The proportion between the crowding and hoisting action can be regulated at the will of the operator.

When maximum crowding effort is desired, the crowd brake 41 is completely released and the crowd clutch 45 is engaged so as to transmit power from the shaft 34 to the crowd drum and from there through the chain transmission to the shipper shaft. The total crowding effort obtainable in this way is considerably in excess of that possible heretofore with a shovel of equivalent size and power.

With the hoist cable reeved to the crowd drum the shovel of this invention is more flexible than prior shovels in meeting varying digging requirements, since provision is made not only for increased crowding effort but also for high speed hoisting after the initial part of the stroke, as

by applying the crowd brake to the desired extent.

As to the crowd drum 42, it should be noted that said drum may alternatively be used to operate a crowd cable extended to a drum on the shipper shaft, in which case the hoist cable is also reeved to the drum on the shipper shaft, as in certain prior shovels.

Still further, as above mentioned, it is contemplated that the hoist cable may be dead-ended on the boom, and the crowding effort secured through the chain transmission between the crowd drum and the shipper shaft.

As a result of the capability of conversion between two or more types of operation, a given shovel mechanism may be designed to meet a very much wider variety of operating conditions than has been possible heretofore. The alternative conditions make possible high speed digging action which is desirable from the standpoint of production where light earth and similar excavation is encountered, and alternatively an improved capability for handling rock or other heavy work where that type of excavation is encountered.

I claim:

1. In a power shovel having a boom, a dipper with its dipper stick mounted on the boom for hoisting and crowding movement, and crowd mechanism also mounted on the boom for effecting crowding action of said stick, a power shaft, a hoist drum mounted coaxially with the power shaft and adapted to be actuated thereby. a

crowd drum also mounted coaxially with said shaft and adapted to be actuated thereby, crowd drive means carried by said crowd drum and connected with the crowd mechanism on the boom,

and a hoisting cable associated with the dipper 5 and having one end reeved upon the hoist drum and the other reeved upon the crowd drum, whereby the actuation of the hoist drum from said shaft efiects the crowding operation by means of said cable.

2. A construction according to claim 1, wherein clutch means are provided for actuating both of said drums from said shaft.

3. A construction according to claim 1, wherein a controllable brake is provided for said crowd drum, whereby to controllably vary the relation between the crowding and hoisting eiIects of said cable.

4. A construction according to claim 1, wherein a clutch is provided for controllable actuation of said hoist drum from said shaft, and a controllable brake is provided for said crowd drum, whereby the hoisting action may be absolutely controlled and the hoisting and crowding actions may be relatively controlled.

5. A construction according to claim 1, wherein independently controllable clutches are provided for separate actuation of both of said drums from said shaft, whereby the crowding and hoisting actions are efiected directly through one shaft 10 and one cable.

15 on said drums is from opposite sides thereof,

whereby said crowd drum can be subjected to a crowding action from the hoist cable solely, and also from said cable in conjunction with a drive directly through the crowd clutch from said 20 shaft, at the will of the operator.

' WILLIAM M. HUSTON.

CERTIFICATE OF CORRECTION. Patent No. 2, 9,700. January 18, 19th.

WILLIAM H. HUSTON.

It is hereby certified that error appesrs in the printed specification of the above numbered patent requiring correction as follows: Page 3, first column, line 9, for "effects" read --affec ts--; and that the said Letters Patent should be read with this correction therein that the same msy confoxm to the record of the case in the Patent Office.

Signed and sealed this llthday of April, A. D. 191m.

Leslie l'razgpt (Seal) Acting Commissioner of Patents. 

